This invention concerns a novel polymeric composition. Specifically, this invention concerns a novel polycarbonate composition prepared from dihydroxyaryl ketones.
Polycarbonate resins are well-known in the prior art. Exemplary of the known polycarbonate resins are the polycarbonates of bisphenol-A as described in U.S. Pat. No. 3,028,365. Similarly, information exemplary of the polycarbonate resins known in the art can be found in Volume 18 of the Kirk-Othmer Encyclopedia of Chemical Technology, pages 479-493 (3rd Edition). Polycarbonate resins are useful thermoplastics because of their desirable physical properties. Those physical properties for which polycarbonates are most often employed are impact strength or toughness and clarity. Polycarbonate resins are also known for their ductility and relatively high softening temperatures.
In certain applications, it has been found desirable to incorporate ester moieties in the backbone of the polycarbonate resin. Thermoplastic resins comprising both ester and carbonate linkages in their backbone chain are known as polyestercarbonate resins. Exemplary of such resins are those described in U.S. Pats. No. 3,030,331; 3,169,121; 3,220,976; 4,156,069; 4,278,787; 4,330,662; and 4,360,656. Polyestercarbonate resins have been found to possess higher heat resistance than many carbonate resins. Therefore, the polyestercarbonate resins are often employed in applications requiring exposure to relatively high temperatures.
While the known polycarbonate resins and known polyestercarbonate resin and/or polyestercarbonate resin possessing improved properties, especially a high level of solvent stress crack resistance. Moreover, it is desirable to achieve said increase in solvent stress crack resistance without sacrificing other desirable physical properties such as toughness, impact strength, clarity, etc. normally possessed by polycarbonate and polyestercarbonate resins. Additionally, it is desirable that a resin possessing the higher level of solvent stress crack resistance be capable of easy production and economical use. It is to these and other similar goals that the present invention is directed.